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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Chevy P42 Commercial Chassis 🢒 Engine 🢒 Engine Controls - 6.5L (L57) 🢒 DTC P1125 Accelerator Pedal Position (APP) System

Object Number: 226926 Size: MF
Engine Controls Components L57 EFI
Engine Controls (Cell 22: Fuel Controls 5)
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The Accelerator Pedal Position (APP) module provides a voltage signal that changes relative to the accelerator pedal position. There are three sensors which are located within the APP module that are scaled differently.

Conditions for Running the DTC

The ignition switch in the on position.

Conditions for Setting the DTC

The PCM has recognized an intermittent APP fault and there are no other current APP faults stored.

Action Taken When the DTC Sets
    •  The Service Throttle Soon lamp will not illuminate when one APP DTC sets. The PCM will only illuminate the Service Throttle Soon lamp when multiple APP DTCs set.
    • The PCM records the operating conditions at the time the diagnostic fails. This information is stored in Failure Records.

Conditions for Clearing the MIL/DTC
    • A History DTC will clear after forty consecutive warm-up cycles during which the diagnostic does not fail (the coolant temperature has risen 5°C (40°F) from the start up coolant temperature and the engine coolant temperature exceeds 71°C (160°F) during that same ignition cycle).
    • Use of a scan tool will clear the DTC codes.

Diagnostic Aids

There are no driveability issues associated with the APP module unless a DTC is present. The most likely cause of this DTC are poor connections or the sensor itself. The least likely is a PCM problem.

A DTC P1125 will set along with multiple APP DTCs. All other DTCs should be diagnosed first.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. This step determines if DTC P1125 is a hard failure or an intermittent condition.

Step

Action

Value(s)

Yes

No

1

Important: Before clearing the DTCs, use the scan tool Capture Information function to save the Freeze Frame and the Failure records for reference. The control module's data is deleted once the Clear DTC Information function is used.

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Disconnect the APP sensor electrical connector.
  2. Ignition ON, engine OFF.
  3. With a DMM,J 39200 ,connected to ground, check all APP 5 volt reference circuits at APP harness.

Is voltage less than specified value?

4.8 V

Go to Step 4

Go to Step 3

3

DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If additional DTCs were stored refer to the applicable DTC table(s) first.

Are any additional DTCs stored?

--

Go to the Applicable DTC Table

Go to Diagnostic Aids

4
  1. Turn the ignition OFF.
  2. Disconnect the PCM and check the 5 volt reference circuit for a short to ground.
  3. If the 5 volt reference circuit is shorted to ground, repair it as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you perform a repair?

--

Go to Step 6

Go to Step 5

5

Important: The new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Is the action complete?

--

Go to Step 6

--

6
  1. Using the scan tool, clear the DTCs.
  2. Start the engine.
  3. Allow the engine to idle until the normal operating temperature is reached.
  4. Select the DTC and the Specific DTC functions.
  5. Enter the DTC number that was set.
  6. Operate the vehicle with the conditions for setting this DTC until the scan tool indicates the diagnostic Ran.

Does the scan tool indicate the diagnostic Passed?

--

Go to Step 7

Go to Step 2

7

Does the scan tool display any additional, undiagnosed DTCs?

--

Go to the Applicable DTC Table

System OK